While femtocells are becoming popular, they are assumed to be installed in houses or offices. Femtocell operation is assumed in such a way as to limit radio communication terminals allowed to communicate with a femtocell; that is, a radio communication terminal that can use a femtocell is only a radio communication terminal whose ID (identifier) has beforehand been registered in a Mobility Management Entity (MME).
Thus, a radio communication terminal whose ID is not registered cannot communicate with a femtocell, even if it is located indoors. This may result in a decrease in the terminal's received power from a macrocell and a decrease in its throughput. Besides, a radio communication terminal that cannot communicate with a femtocell becomes a source of interference on a radio communication terminal now communicating with the femtocell.
To solve the above-noted problem, in Japanese Unexamined Patent Application Publication No. 2010-147682, a method is adopted in which a propagation loss between a radio communication terminal and a femtocell is calculated at the femtocell and, if the propagation loss is less than a given value, a handover of the terminal from a macrocell to the femtocell is executed. Thereby, this method makes only terminal actually located indoors connect to the femtocell and prevents a radio communication terminal located indoors from being a source of interference.